Sealing member for liquid container

Abstract

A liquid container disclosed herein prevents the spattering of ink at the time of peeling a sealing member from a seal surface. A peeling end portion is devised such that the peeling load F gradually decreases as the peeling proceeds over first and second seal surfaces toward an end. The peeling load needs to gradually decrease over a peel ending distance at a rate of at most 0.02 kgf/mm. Such a low peeling load-decreasing rate is realized by gradual width reductions of an end portion of the seal surface, or by predetermining the manner of adhesion between the sealing member and the seal surface, such that the adhesion force per unit area gradually decreases with the progress toward an end of the seal surface. Such slow and gradual reductions in adhesion force allow a user who peels the sealing member to correspondingly adjust the speed of peeling hand movement in a final stage of the peeling. Therefore, at the time when the sealing member finally separates from the seal surface, the sealing member held by the user has been sufficiently loosened back so that substantially no backlash occurs. The spattering of ink from the sealing member and the staining of the surrounding area are thereby prevented.

What is claimed is:  
     
       1. A liquid container sealed by a sealing sheet member, comprising: 
       a container chamber containing a liquid;  
       an opening portion provided in an outer surface of the container chamber; and  
       a first seal surface formed around the opening portion for sealing the opening portion with the sealing sheet member, a portion of the first seal surface at a position of a final stage of peeling of the sealing sheet member from the first seal surface being formed in such a shape that width thereof decreases toward an end.  
     
     
       2. The liquid container according to claim  1 , further comprising a second seal surface formed between the first seal surface and the opening portion, the second seal surface adhering to the sealing sheet member and having an annular shape that surrounds the opening portion and has a substantially consistent width. 
     
     
       3. The liquid container according to claim  1 , wherein the first seal surface has an arcuate portion and a width-reducing end portion. 
     
     
       4. The liquid container according to claim  1 , wherein the opening portion is provided in a lower portion of a side surface of the liquid container, and wherein a width-reducing end portion of the first seal surface extends upward from the opening portion. 
     
     
       5. The liquid container according to claim  1 , wherein the opening portion is provided in a lower portion of a side surface of the liquid container, and wherein a width-reducing end portion of the first seal surface extends downward from the opening portion. 
     
     
       6. The liquid container according to claim  1 , wherein the opening portion is provided in a lower portion of a side surface of the liquid container, and wherein a width-reducing end portion of the first seal surface extends in each of upward and downward directions from the opening portion. 
     
     
       7. The liquid container according to claim  1 , further comprising an atmosphere communication hole that introduces external air, and a second sealing member that seals the atmosphere communication hole. 
     
     
       8. The liquid container according to claim  1 , further comprising an atmosphere communication hole that introduces external air, the atmosphere communication hole being sealed by the same sealing member that seals the opening portion. 
     
     
       9. The liquid container according to claim  1 , wherein the liquid container is for use as an ink cartridge of an ink jet printing apparatus. 
     
     
       10. The liquid container according to claim  1 , wherein the first seal surface has a width-reducing pointed end portion. 
     
     
       11. A liquid container sealed by a sealing sheet member, comprising: 
       a container chamber containing a liquid;  
       an opening portion provided in an outer surface of the container chamber; and a first seal surface formed around the opening portion for sealing the opening portion with the sealing sheet member that is peeled off when the liquid container is used, the first seal surface having a configuration such that the adhesion force between the first seal surface and the sealing sheet member decreases relative to peel distance at a rate of at most 0.02 kgf/mm, in a final stage of the peeling of the scaling sheet member from the first seal surface wherein the adhesion force-decreasing rate relative to peel distance in the final stage of the peeling of the sealing sheet member from the first seal surface is preset to at most 0.02 kgf/mm by gradual width reductions of a portion of the sealing sheet member at a position of the final stage.  
     
     
       12. The liquid container according to claim  11 , wherein the adhesion force-decreasing rate relative to peel distance in the final stage of the peeling of the sealing sheet member from the first seal surface is preset to at most 0.02 kgf/mm by gradual reductions in the adhesion force per unit area of the first seal surface at a position of the final stage. 
     
     
       13. The liquid container according to claim  11 , wherein the adhesion force decreases relative to peel distance at a rate of at most 0.016 kgf/mm, in a final stage of the peeling of the sealing sheet member from the first seal surface. 
     
     
       14. The liquid container according to claim  11 , wherein the adhesion force decreases relative to peel distance at a rate of at most 0.02 kgf/mm just before the sealing sheet member is perfectly peeled from a first seal surface. 
     
     
       15. A liquid container, comprising: 
       a case cartridge having a pair of opposing side walls, a pair of opposing end walls, a bottom wall and a lid member mounted at an upper edge of the pair of side walls and the pair of end walls, a liquid opening in a portion of one end wall near the bottom wall and an air opening in one of the other end wall of the pair of end walls and one side wall of the pair of side walls near the lid member;  
       a sealing surface disposed around the liquid opening; and  
       a sealing member adhered to the sealing surface, the sealing surface configured such that a force of adherence between the sealing surface and the sealing member decreases in a direction of removal of the sealing member, wherein the sealing surface has a width-reducing end portion extending in the direction of removal of the sealing member.  
     
     
       16. The liquid container according to claim  15 , wherein the sealing surface comprises: 
       an inner seal surface surrounding the liquid opening; and  
       an outer seal surface surrounding the inner seal surface.  
     
     
       17. The liquid container according to claim  16 , wherein the outer seal surface has a rain drop shape comprising an arc portion at an upstream side and a width-reducing portion at a downstream side in the direction of removal of the sealing member. 
     
     
       18. The liquid container according to claim  17 , wherein an end of the width reducing portion may be one of pointed, blunted, and rounded. 
     
     
       19. The liquid container according to claim  16 , wherein the force of adherence between the sealing surface and the sealing member decreases at a rate no greater than 0.02 kgf/mm in final stages of removal of the sealing member. 
     
     
       20. The liquid container according to claim  15 , wherein the air opening is in the other end wall of the pair of end walls and the sealing member seals both the air opening and the liquid opening.